Objective:

Small public water systems (PWS) face numerous technical, operational, financial, and regulatory challenges in producing safe and reliable drinking water. Given the challenges faced by small PWS, there is an urgent need for treatment technologies that remove groups of chemical contaminants, are energy efficient, are simple and affordable to operate, generate residual streams that are easy to dispose of, and improve compliance with state and federal rules. Accordingly, the objective of this project is to identify and test ion exchange processes that can treat groups of chemical contaminants and evaluate their sustainability. The central hypothesis is that ion exchange is an appropriate treatment technology for small PWS because it is robust, selective, and scalable. The objective will be completed by pursuing four specific aims:

Identify combined anion and cation exchange processes that can treat groups of chemical contaminants in an environmentally friendly way;

Develop an ion exchange process model that includes multi-contaminant treatment and regeneration efficiency;

Demonstrate the performance of the ion exchange treatment and regeneration processes through pilot-scale testing at a small PWS; and

Evaluate the environmental, human health, and economic impacts of the ion exchange treatment and regeneration processes through life cycle assessment (LCA) and life cycle cost analysis (LCCA).

Approach:

The approach will include laboratory-scale studies that systematically evaluate the selectivity of combined anion and cation exchange for contaminant removal and regeneration; model development to incorporate multi-contaminant treatment by combined anion and cation exchange and different regeneration processes; pilot study at a small PWS in which different regeneration strategies will be systematically evaluated; and LCA and LCCA that holistically evaluates sustainability of different process designs under various operational conditions.

Expected Results:

Successful completion of this project is expected to have multiple benefits to small PWS. The outputs will include: data on removal and regeneration efficiency for combined anion and cation exchange for simultaneous treatment of multiple contaminants; new mathematical model that will allow the innovative ion exchange process to be extended to other contaminants and conditions; and evaluation results of life cycle environmental and human health impacts and life cycle costs of the new ion exchange process. This project is expected to strengthen communities in two ways: 1) it provides a solution to meet the urgent need for small PWS in producing safe and reliable drinking water through its technological innovation; and 2) it evaluates the potential environmental and human health impacts through LCA so that problems will not shift from one environmental media to another. Finally, it is expected that the results will facilitate improved risk assessment through experimental data and modeling tools that quantify the treatment efficiency of groups of chemical contaminants.

Progress and Final Reports:

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.